I just made an extension function to replace it lo...

# arrow-contributors

[Satyam Agarwal]

I just made an extension function to replace it locally.

inline fun <reified A, reified B> Either<Throwable, A>.product(f: () -> Either<Throwable, B>): Either<Throwable, Tuple2<A, B>> {
    return this.flatMap { a -> f().map { b -> a toT b } }
}

[raulraja]

is this coming from an imported extension?

[Satyam Agarwal]

you mean the error ? then yes, the mproduct is imported from arrow.core.extensions.either.monad.mproduct

[Satyam Agarwal]

implementation("io.arrow-kt:arrow-core-data:$arrowKtVersion")
    implementation("io.arrow-kt:arrow-core:$arrowKtVersion")
    implementation("io.arrow-kt:arrow-fx-coroutines:$arrowKtVersion")
    implementation("io.arrow-kt:arrow-fx-kotlinx-coroutines:$arrowKtVersion")
    implementation("io.arrow-kt:arrow-fx:$arrowKtVersion")

are dependencies I am pulling atm

[Satyam Agarwal]

i will remove arrow-fx and arrow-fx-kotlinx-coroutines once I have removed IO completely from project .

[raulraja]

We are debating if those methods are useful since in suspension we have not found a use case for it that can't be done in place with easier syntax. Do you have a small example on how you are using mproduct ? I'd like to explore and see if that and others are worth keeping around for 1.0

[Satyam Agarwal]

this is a pattern I do for all my ktor routers

ParametersValidator
            .validateId(id)
            .toEither()
            .mproduct { tokenValidator.validateRequest(authorization) }

[Satyam Agarwal]

and then I use the destructured tuple as input to the service layer

[Satyam Agarwal]

Also Either.fx { } is deprecated, yet it is used the migration readme, and arrow website.

@Deprecated("Fx blocks are now named based on each datatype, please use `either { }` instead",
  replaceWith = ReplaceWith("either.eager<L, R>(c)"))
fun <L, R> Either.Companion.fx(c: suspend MonadSyntax<EitherPartialOf<L>>.() -> R): Either<L, R> =
  Either.monad<L>().fx.monad(c).fix()

`

alternative given in either.eager which gives compilation error :

Restricted suspending functions can only invoke member or extension suspending functions on their restricted coroutine scope

[Satyam Agarwal]

tried just either { } as well, thats same too.

[Satyam Agarwal]

I understand Either.fx is much better, but I don’t know why, I just love chaining methods, using extra syntax like map, flatmap, mproducts. 😅